Aiming a laser at an aircraft is a serious safety risk and violates federal law. Many high-powered lasers can completely incapacitate pilots who are trying to fly safely to their destinations with hundreds of passengers. The Federal Aviation Administration is working with federal, state, and local law enforcement agencies to pursue civil and criminal penalties against individuals who purposely aim a laser at an aircraft. The potential that terrorists could seek to disrupt air travel through the use of lasers is real.
Federal Aviation Administration researchers have compiled a database containing more than 3,000 reports of aircraft laser illumination events over a 20-year period. These reports describe the illumination of military and civilian aircraft by lasers, including law enforcement and medical evacuation flights. No accidents have been attributed to the illumination of crewmembers by lasers, but given the sizeable number of reports and debilitating effects that can accompany such events, the potential does exist. On December 2013 a commercial airline pilot and copilot averted a disaster by landing an airplane safely at Palm Beach International Airport after a blinding laser was pointed at the cockpit from the ground, according to the Palm Beach County, Fla., Sheriff's Office. On Dec. 26, 2013, a commercial flight approached New York's John F. Kennedy International Airport. The pilot of that plane was temporarily blinded by a laser and experienced blurry vision for a week following the incident. On Mar. 21, 2013, a 27-year-old man pointed a bright green laser at the pilot of a Columbus, Ohio, Division of Police helicopter. The prosecutor stated at sentencing that “the blinding effect when the laser beam came through the helicopter's windshield could have caused a crash in a heavily populated residential area.” The subject stated that he pointed the laser because he was bored. He was sentenced to 45 days in jail plus 18 months probation. The security-council chair for the Airline Pilots Association has been struck by lasers on five separate occasions during his career. The most serious of the laser strikes occurred 45 seconds prior to landing a CJR-700 aircraft with 67 passengers and four crew members on board in 2011. The captain reported temporary blindness and disorientation.
Sudden exposure to laser radiation during a critical phase of flight, such as on approach to landing or departure, can distract or disorient a pilot and cause temporary visual impairment. Permanent ocular damage is unlikely since the majority of incidents are brief and the eye's blink response further limits exposure. In addition, considerable distances are often involved, and atmospheric attenuation dissipates much of the radiant energy.
Although lasers have many legitimate outdoor uses, such as in astronomical research, deep-space communications, orbital satellite imaging, and outdoor displays to attract and entertain the public, the misuse of laser devices poses a serious threat to aviation safety. Aviators are particularly vulnerable to laser illuminations when conducting low-level flight operations at night. The irresponsible or malicious use of laser devices can threaten the lives of flight crews and passengers.
FAA flight simulator studies, however, have shown the adverse visual effects from laser exposure are especially debilitating when the eyes are adapted to the low-light level of a cockpit at night. Similar to a camera flash at close proximity or the high-beam headlights of an oncoming car, recovering optimal visual performance after exposure to laser light may take from a few seconds to several minutes. Besides startle and distraction, the three most commonly reported physiological effects associated with laser exposures are: Glare—Obscuration of an object in a person's field of vision due to a bright light source located near the same line of sight; Flashblindness—A visual interference effect that persists after the source of illumination has been removed; and Afterimage—A transient image left in the visual field after an exposure to a bright light.
Laser activity in navigable airspace is continually monitored to better define the nature of the threat from outdoor lasers. The number of laser events increased over 300% from 2005 to 2008. This increase may be due to heightened awareness of the problem by flight crewmembers, the introduction of an authorized reporting process, and the increased availability of high-output, handheld laser devices. Once only marketed as “laser pointers” and used for pointing out topics of interest in slide presentations with output power from 1 to 5 mW, handheld laser devices can now be purchased over the Internet with output power as high as 500 mW. While the Food and Drug Administration prohibits the sale of “laser pointers” that exceed 5 mW, it does not prohibit the sale of more powerful, handheld lasers, if they are equipped with the appropriate labels and safety mechanisms.
The latest reports indicate that aircraft illuminations by handheld lasers are primarily green (91%) in color, as opposed to red (6.3%), which was more common a few years ago. This is significant because the wavelength of most green lasers (532 nm) is close to the eye's peak sensitivity when they are dark-adapted. A green laser may appear as much as 35 times brighter than a red laser of equal power output. Due to this heightened visibility and increased likelihood of adverse visual effects, illumination by green lasers may result in more events being reported.
Illumination reports often describe several types of adverse effects. These include visual effects (8.2%), pain and/or possible injury (1.6%), and operational problems (3.2%). Operational problems include momentary distraction, disorientation resulting in another pilot assuming control, aborted landings, loss of depth perception, and shutting down of runways due to multiple laser strikes. While only 16.5% of all cockpit illuminations occurred below 2,000 feet (Laser-Free Zone), these incidents accounted for 31% of all visual effects, 42% of all pain or injuries, and 42% of all operational problems reported. Low-attitude illuminations, therefore, result in a greater risk to aviation safety.
Studies have also shown that almost 70% of all incidents occurred between 2,000 and 10,000 feet AGL, 22% occurred in November and December, and 70% happened between the hours of 7 and 11 pm. There is a real and urgent need to develop technologies that could prevent the ability for laser devices to be used by criminal or terrorist elements to promote aviation safety.